Technological Field
The present invention relates to a technique for applying a lubricant to a photoreceptor drum of an image forming apparatus.
Description of the Related art
Image forming apparatuses having various functions, such as copying, scanning, faxing, and boxing, are widely used. Such image forming apparatuses may also be referred to as “multi-function peripherals (MFP)”.
It has been performed that a lubricant is applied to a photoreceptor drum of an image forming apparatus to protect, from wear, members such as the photoreceptor drum itself and an intermediate transfer belt to be in contact with the photoreceptor drum. JP 2009-15229 A, JP 2007-292996 A, JP 2003-36011 A, JP H7-311531 A, and JP 2007-286246 A each disclose an invention for applying a lubricant to a photoreceptor drum.
An image forming apparatus described in JP 2009-15229 A includes: a lubricant applicator including a rotating member that scrapes and applies a solid lubricant to a surface of an image carrier; a storage that stores at least image forming information that is a total rotation time of the image carrier or a total rotation time of the rotating member; and a controller enabled to change a rotational speed of the rotating member during image formation and variably control the rotational speed of the rotating member on the basis of the information stored in the storage.
An image forming apparatus described in JP 2007-292996 A includes: an image carrier; a lubricant applicator that is a rotating body for applying a lubricant to the image carrier; and a charger that forms a latent image on a surface of the image carrier. In a case where the image carrier linear speed is variable and the image carrier linear speed is high, the linear speed of the rotating body (the lubricant applicator) is reduced.
An image forming apparatus described in JP 2003-36011 A includes a cleaning device that removes toner remaining on a photoreceptor drum after an image is formed by transferring a toner image formed on the photoreceptor drum enabled to rotate in at least two or more circumferential speeds of a first circumferential speed and a second circumferential speed higher than the first circumferential speed. When the photoreceptor drum rotates at a first circumferential speed VA in image formation, a cleaning brush that applies a lubricant is rotated at a first circumferential speed VB, and when a photoreceptor drum rotates at a second circumferential speed VA′, the cleaning brush is rotated at a second circumferential speed VB′. At this time, there is a relationship of VA<VA′, (VB/VA)>(VB′/VA′).
An electrophotographic recording apparatus described in JP H7-311531 A includes: a lubricant applicator that applies a lubricant on an image carrier such as a transfer belt; a detector that detects an amount of the lubricant on the image carrier; and a controller that controls the lubricant applicator on the basis of a detection result of the detector. Then, when the lubricant is applied to the image carrier, the controller controls the lubricant applicator so that application operation is repeated until the detection result of the detector reaches a reference value of the amount of the lubricant on the image carrier.
A lubricant applicator included in an image forming apparatus described in JP 2007-286246 A includes a lubricant molded body and a brush-like roller. The brush-like roller rubs and scrapes the lubricant molded body while rotating, and applies the lubricant to a surface of an image carrier, and an amount of toner input to a cleaner is adjusted, and lubricant application is controlled depending on each image carrier linear speed.
Maintaining an amount of application of a lubricant to a photoreceptor drum, in other words, an amount of consumption of the lubricant in an appropriate amount is necessary to appropriately protect the photoreceptor drum and the like.
However, when a speed at which an image forming apparatus prints an image on a sheet (hereinafter referred to as “process speed”) is changed, the amount of consumption of the lubricant may change from the appropriate amount.
When the amount of consumption of the lubricant changes to be greater than the appropriate amount, the lubricant may be exhausted earlier than planned, and there is a case where the photoreceptor drum and the like are not appropriately protected. On the other hand, when the amount of consumption of the lubricant changes to be less than the appropriate amount, the lubricant cannot be applied to a surface of the photoreceptor drum as much as necessary, and there is a case where the photoreceptor drum and the like are not appropriately protected.